Meaning

noun a widely distributed system consisting of all the cells able to ingest bacteria or colloidal particles etc, except for certain white blood cells

noun a rare heavy polyvalent metallic element that resembles manganese chemically and is used in some alloys; is obtained as a by-product in refining molybdenum

noun ancient Egyptian sun god with the head of a hawk; a universal creator; he merged with the god Amen as Amen-Ra to become the king of the gods

originEtymology tree English re Old English -as Middle English -es English -s English res From re + -s.

Etymology from Wiktionary, CC BY-SA 3.0